The invention concerns a double-counterpoised flywheel for an internal combustion engine. Such a double-counterpoised flywheel includes a counterweight on the engine side and a counterweight on the transmission side. The counterweights allow limited mutual rotation through the intermediary of elastic members. A damping system is arranged between the two counterweights, and parallel to the elastic members. The two counterweights bear on each other radially and axially through an antifriction bearing. The inner race of the antifriction bearing is mounted between a stop face of a counterweight, and a holder disk secured to the end face of the counterweight on the power take-off side. In this regard, reference is made to DE 34 48 480 C2.
Double-counterpoised flywheels are accessory components for automobiles, serving to enhance travel comfort by extensively precluding rotary oscillations from being transmitted from the engine to the transmission. In this role, a perfect technical function is demanded of them. But at the same time they are a mass-produced article. A low-cost of manufacture is important in the hotly contested accessory business. In such manufacture, perfect operation must always be guaranteed.
One of the sensitive spots of double-counterpoised flywheels is the bearing and its environs. In the categorical double-counterpoised flywheel, primary mass and secondary mass bear on each other through the intermediary of a single bearing. Therefore, particular significance attaches to this bearing. Its positioning and fixing are decisive for the perfect operation and long service life of the entire assembly.
The known embodiments leave much to be desired with regard to the fixing and positioning of the inner race of the bearing. In the categorical, prior double-counterpoised flywheel, the inner race of the sole bearing is mounted between a stop face machined on the primary mass and extending in axially perpendicular fashion, and the holder disk. In turn, the holder disk is screw-joined to the double-counterpoised flywheel--and to its hub. However, this embodiment is expensive. For instance, the holder disk must be provided with screw holes, which holes are countersunk for flat head screws. The hub of the primary mass needs to be provided with matching tapped holes for receiving the countersunk screws. Maximum care must be extended to the correct positioning of the holes and of the tapped holes aligned on them. This is expensive, thus boosting the cost of production. Manufacturing inaccuracies may cause problems, which in unfavorable cases may impair the service life of the bearing and thus of the entire assembly.
The problem underlying the invention is to design a double-counterpoised flywheel in such a manner that the manufacturing costs can be reduced with respect to design and mounting of the holder disk, the service life of the assembly will be improved, and the functioning of the assembly remains perfect nonetheless.